The invention is concerned with novel heteroaryl carboxamides of formula I and their use as inhibitors of coagulation factor Xa. Factor Xa is a serine endopeptidase composed of two disulfide-linked subunits that converts prothrombin to thrombin in the blood coagulation cascade. Inhibitors of factor Xa can be used for treating thrombotic disorders by inhibiting the formation of thrombin. Prior to the present invention, other inhibitors of factor Xa have been suggested for the inhibition of the formation of thrombin and for the treatment of related diseases. However, there is still a need for novel factor Xa inhibitors which exhibit improved pharmacological properties, i.e., an improved selectivity towards thrombin.